Mucle work, energy and power

Question 1

Definition of mechanical energy

Answer 1

Masure of the state of a body at an instant in time as to its ability to do work

Question 2

Definition of mechanical work

Answer 2

Measure of energy flow from one body to another

Question 3

This law states that the algebraic sum of all the energy flows must equal the energy change of that segment.

Answer 3

Law of conservation of energy

Question 4

How do you calculate the muscle power at a given joint?

Answer 4

At a given joint, the muscle power is the product of net muscle moment and joint angular velocity: 𝑃 = 𝑀 𝜔

Question 5

When is the muscle power positive?

Answer 5

When the muscle moment is in the same direction as the angular velocity of the joint

Question 6

When is the muscle power negative?

Answer 6

When the muscle moment is in opposite direction to the movement of the joint

Question 7

True or false?

If during a human body movement the net mechanical muscle work done is zero, then the during the movement was zero.

Answer 7

False.

During a movement the power (and work) will reverse sign several times. If you move a segment doing negative work and then you revserse the movement doing positive work, the net work is zero.

Question 8

Is the mechanical energy absorbed or generated when the muscle contracts eccentrically?

Answer 8

Absorbed from the segment to the muscle

Question 9

Is the mechanical energy absorbed or generated when the muscle contracts concentrically?

Answer 9

Generated from the muscle to the segment